So if you didn't know, your research, fossil extraction, and expedition buildings are "linked" throughout the island. You just have to have one built on the island to access them. Say you find yourself on the 2nd island bleeding money. Hopefully you have a fossil storage, expedition is not required for this.

Now what you do is head back to your first island where you have both of those buildings. Start doing fossil expeditions, save all the ones that just sell for cash! Now head back to second island, and viola, there are some fossils to sell.

Do all your research on a previous island.

To touch on how you building are linked, your upgrades are linked too. If you have a fossil building with upgrades, ie "extraction time, and "Inventory space" your new fossil building has those upgrades, plus whatever you add to it.

I believe it only works for fossil, expedition, and research.